418 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XII. 



that the buck must be kept in a separate hutch till the young are able to 

 I'un about for tiie same reason. This trait appears to be characteristic of 

 the Rodeuha generally. Nearly all the squirrels that came about our houses 

 and gardens are males. 



E. H. AITKEN. 

 Uran,29<A September, 1898. 



No. X.— A WASP AND A FLY. 



The following incident, bearing on the most interesting of all questions in 

 Natural History, namely, animal intelligence, seems worth recording. I hope 

 it may stimulate entomological members to collect more evidence, joro or con. 

 About the beginning of September a large reddish-brown wasp {Eumenes conica, 

 I think) having built a chatty-shaped clay cell on my bed-room door and 

 stocked it with caterpillars and closed it, began another. As it flew in with a 

 pellet of clay, I noticed that it was closely pursued by a fly not much larger 

 than a common house-fly, but curiously marked with longitudinal gray stripes. 

 When it commenced work, the fly alighted, at a distance of four or five 

 inches, and waited. When it finished and went off for more clay, the fly 

 instantly flew up to the cell, but after a moment's examination, retired again 

 to a distance of four or five inches and waited, facing the cell. Again the 

 wasp came with a pellet of clay, worked it in, and went off for more. This 

 time the fly did not examine the cell, but waited where it was. Just at this 

 point the Boy announced breakfast, and I went away, supposing the wasp 

 would take balf-a-day to finish the cell. What was my disgust when I 

 came back to find the cell finished and the fly gone. In ordinary course I 

 believe the cell should have been stocked with caterpillars in the course of the 

 next day ; but as I went to Bombay, I did not see this being done. When 

 I returned, however, the cell was sealed up. No morn were made at that 

 place which seemed strange, for they are generally built in clusters of six or 



seven. 



A week later I broke open the cells and found in the first a pupa, evidently, 

 from the size, a wasp pupa, enclosed in a loose bag of silk. In the second cell 

 there was nothing. The larvae of some flies develop with remarkable rapidity, 

 and it is conceivable that in this case the egg laid by the fly might have 

 produced a voracious larva, which might have cleared the larder, devoured its 

 richtful owner, passed through a rapid pupa stage and escaped by some hole 

 which escaped my notice, all in the course of ten days. But in that case there 

 must have been remains, pupa case, excreta, &c. There was nothing of the 



kind. 



It was clear that the wasp had sealed the cell without stocking it. Had it 

 discovered that it was being cuckolded ? The thing is not impossible. It may 

 have caught the fly in the cell, in the act of depositing its egg, or it may 

 have observed the foreign egg as it was about to lay its own ; and it may have 



